To use the utility database you must specify the user ID DBA. The password for the utility database is held in a file named util_db.ini, which is stored in the server executable directory. As this directory is on the server, you can control access to the file, and thereby control who has access to the password.
The util_db.ini file has the following contents:
[UTILITY_DB] PWD=password
Use of the utility_db security level relies on the physical security of the computer hosting the database server, since the util_db.ini file can be easily read using a text editor.